Embodiments relate generally to heat and mass exchangers and, more particularly, to an energy recovery ventilator (“ERV”) that attaches directly to an existing furnace, fan coil or air handler and uses two duct connections for recovering energy from indoor air.
An ERV is generally used with a heating or cooling system to exhaust stale air from a stale air space to a fresh air space and bring in fresh air from the fresh air space to the stale air space while exchanging heat or cool energy, thereby reducing heating or cooling requirements. Typically, an ERV includes a heat and mass exchanger contained in a housing for exchanging heat or cool energy. The exchanger may be rotating or stationary. When the ERV is used with a heating or cooling system, an outside air stream ducted from the outdoors and a stale room air stream from the return air duct or furnace, fan coil, or air handler separately enter the ERV and pass through the heat and mass exchanger. Within the heat and mass exchanger, energy from the stale room air stream is transferred either to or from the outside air stream. The outside air stream then exits the ERV to the supply air duct or furnace, fan coil, or air handler as a fresh air stream. The stale room air stream then exits the ERV to the outdoors through a duct as an exhaust room air stream.
Most residential ERVs are mounted on a wall or ceiling and generally require four duct pipes to exchange cool or heat energy with an air handler system. In an example, the outside air stream and the stale room air stream enter the housing through duct pipes connected to two air flow openings in the housing. The fresh air stream and the exhaust room air stream exit the housing through two other duct pipes connected to two other air flow openings in the housing. These ERVs are standalone heat and mass exchangers that are remotely mounted from the heating or cooling system and are not designed to be connected directly to a furnace or an air handler in a heating or cooling system. As connected to the heating or cooling system, this ERV is costly and cumbersome to install as it requires the installation of four separate duct pipes to carry each air stream to or from the fresh air or stale air spaces. Moreover, these ERVs require low voltage wall controls and an available power receptacle, which further complicates the installation process.
Other ERV's are configured to connect directly to a furnace or air handler blower compartment, eliminating the need for the four duct pipes. These ERV's, however, are prone to allow increased levels of stale air recirculation in the heating or cooling system.